1. Field of the Invention
The invention relates to the preparation of optionally substituted arylpyruvic acids by reaction of optionally substituted arylhalogenmethyl compounds with carbon monoxide in an alcohol/water mixture in the presence of metal carbonyls and of an alkali hydroxide.
2. Discussion of the Prior Art
According to J. Anatol. Synthesis 1971, No. 10, pp. 538-39, arylpyruvic acids may be obtained from .alpha.-aminonitriles or cyanohydrins from the .alpha.-hydroxy-N-tert-carboxylic acid amides by oxidation. This and other synthesis routes require use of starting materials which are not readily available. Moreover, these routes entail numerous intermediate stages or produce only small yields.
In German Auslegeschrift DAS No. 26 00 541 it is proposed to convert arylmethylhalides to arylpyruvic acid with carbon monoxide in the presence of metal carbonyl compounds, particularly cobalt, in the presence of from 1 to 4 mols of alkaline earth bases. This results in a number of undesired by products which render working-up difficult. In column 3, lines 61-64, of that German application, it is expressly stated that arylpyruvic acid will not form when the alkaline-earth bases are replaced with alkali metal bases.
Thus, there has been a need for preparing arylpyruvic acids by simple and economically feasible methods.